不同化学调控剂对甘蔗节间伸长及糖分积累的影响.

[Objective] The present paper aimed to investigate the effects of growth-promoting chemical regulations on internode elongation and its sugar accumulation in sugarcane internode, and to analyze the relationship between cane yield and important agronomic traits. The results will provide reference for the directional chemical regulation of sugarcane agronomic characters and the improvement of cultivation techniques of high yield and high sugar content. [Method] In the study, sugarcane excellent cultivar GT58 was used as planting material in a 2-year field plot trials, water spraying on leaves was used as control group ( CK), and different growth-promoting chemical regulators were used as chemical regulators treated groups. They were respectively calcium nitrate(A),boric acid(B),potassium dihydrogen phosphate(C),compound sodium nitrophenolate(D),gibberellin(E),composed of gibberellin and compound sodium nitrophenolate(F),composed of gibberellin,calcium nitrate, boric acid, potassium dihydrogen phosphate, compound sodium nitrophenolate ( G) . The plant height, intemode elongation rate, sugar content and yield of sugarcane were measured at different growth stages after chemical regulator was applied in intemode elongation period. [ Result] The intemode elongation rate treated with different growth-promoting chemical regulators was 1. 22 - 1. 67 cm/ d. The average internode number was 21. 30 -23. 90,and the average intemode length was 11. 41 -12. 41 cm, and those of E and G treatments containing gibberellin were extremely significantly higher than CK ( P < 0. 01, the same as below) . The plant height with gibberellin E and G treatments were significantly higher than CK ( P < 0. 05, the same as below), the stem diameter was significantly lower than CK, the effective stem number was lower than CK but the difference was not significant( P > 0. 05), and the final yield was higher than CK. In the process of sugar accumulation in sugarcane intemode, the treatment groups containing gibberellin-containing regulator( E, F and G treatments) could promote the accumulation of sugar in the middle and upper intemode of cane stem, and promote the sugar content in different parts of intemode to reach the level of process maturity, and reduce the reducing sugar content to the level below CK. Correlation analysis showed that there was a weak negative correlation between stem diameter and yield in treated group, and their Pearson's coefficient was only - 0. 082. There was extremely significant positive correlation between millable canes number and yield,as well as plant height. [ Conclusion]The growth-promoting chemical regulators promoted the formation of sugarcane plant height by regulating intemode elongation, thus affecting the correlation between yield, plant height, millable canes number and stem diameter, and realized the improvement of sugarcane yield formation at last. Among them, containing gibberellin chemical regulators could promote intemode elongation and accelerate the rapid accumulation of sugar from the middle intemode to the upper intemode in sugarcane, which had great potential for increasing yield and its sugar content in sugarcane. These can be used in the directional chemical control of agronomic traits and the improvement of high-yield and high-sugar cultivation technology in sugarcane. [ABSTRACT FROM AUTHOR]